The Orientation property allows you to change the orientation of document groups in code. When the Orientation property's value is changed, the OrientationChanged event fires.

Note that the Orientation property value corresponds to the DocumentGroup order (side-by-side or one above another), while context menu items that allow end-users to create a new group specify the splitter orientation, which is the same behavior seen in Microsoft Visual Studio. Thus, if an end user clicks the 'New Horizontal Tab Group', the View's orientation will be vertical and vice versa. The image below illustrates this difference.